WASHINGTON — The real estate industry yesterday added its voice to the growing number of commercial interests that have been complaining about a congressional proposal that would increase the tax rate on income earned by the managing partners of investment firms.

In testimony prepared for the House Ways and Means Committee, Adam Ifshin, president of real estate development firm DLC Management, said that companies like his would not be able to expand as readily — and might never have come to exist at all — if the tax rate were higher than it is now.

Experts on both sides of the carried interest issue testified before packed audiences at the Ways and Means Committee and at the Senate Finance Committee.

Some leading Democrats in the House have proposed to more than double the tax rate on carried interest to the 35 percent range from 15 percent.